<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
		.father {
			width: 300px;
			height: 300px;
			background-color: pink;
		}
		.son {
			width: 400px;
			height: 200px;
			background-color: purple;
		}
	</style>
</head>
<body>
	<div class="father">
		<div class="son"></div>
	</div>
</body>
</html>